In the case of a known withdrawable rack, a protective unit with two movable protective plates—which are displaceable for the release of access openings formed in a cover plate with respect to incoming and outgoing contacts—and two lever arrangements for operating the two protective plates is provided. In this case, each of the two lever arrangements has two levers which are interconnected in an articulated manner, of which a first lever can be operated by means of the switching device and the second lever is coupled to the movable protective plate, the first lever being displaceable in a first phase of the pushing-in movement of the switching device—for pivoting the second lever—and being pivotable in a second phase of the pushing-in movement—without further pivoting of the second lever (EP 0 803 140 B1).
In the case of this known protective unit, the ends of the two first levers that are allocated to the switching device are interconnected in an articulated manner, the linking joint of the two first levers acting simultaneously as the pivot bearing of these levers. To allow the switching device to be pushed into its end position in the withdrawable rack after release of the access openings, the two first levers are displaceable under the effect of the force of the moving-in switching device by the linking joint between the first lever and the second lever being respectively displaceable along a slideway. As this happens, jamming of the linking joint in the slideway as the switching device is pushed further can lead to the lever arrangement being damaged.